RESEARCH: The purpose of this research was to identify the theoretical basis of commonly used intervention strategies for occupational therapy in mental health. The research questions of interest are “What intervention strategies are commonly used by occupational therapy practitioners to treat adults with mental health issues?” “What is the theoretical basis of the said intervention strategies?” and “How do occupational therapy practitioners use theory to guide clinical decision making in mental health practice?”

RATIONALE: Theory should be at the core of all occupational therapy practice. It drives the intervention process by guiding sound, ethical decisions based on client needs and desired outcomes. Previous studies have shown how theory is used in occupational therapy practice, but few have demonstrated the use of theory in mental health practice.

DESIGN: A mixed-methods design with retrospective cohort and ground theory methodologies.

PARTICIPANTS: We analyzed 121 medical records from two mental health facilities. We interviewed 5 occupational therapy practitioners.

METHOD: The first phase was an extraction of all relevant demographic data, therapy goals, status of goal attainment, and intervention strategies utilized. The second phase consisted of interviewing practitioners about the intervention strategies that they used and the theoretical basis of those strategies. An interview guide based on the phenomenon of interest was used to extract qualitative data from occupational therapy practitioners.

ANALYSIS: Quantitative data were nominal (number of therapy goals achieved, frequency of use of various theoretical conceptual practice models, etc.). Therefore, they were analyzed using nonparametric methods, specifically χ² goodness of fit and Pearson χ² analysis. Qualitative data were analyzed using grounded theory procedures, including open, axial, and selective coding in order to develop a grounded theory of occupational therapy practitioners’ perspectives of the process of therapy and the role of theory in this process.

RESULTS: Results indicate that client-centered models, behavioral/cognitive–behavioral model, and the Model of Human Occupation were the three most frequently used occupational therapy theories in mental health practice at the two facilities, χ²(5, N = 357) = 245.67, p < .001. Selection of these three theories was supported in the qualitative findings. Progress toward occupational therapy goals was as follows: 31.22% achieved, 24% in progress, and 45% not achieved. Finally, the data analyses indicated a significant association between theory used and progress toward goals, Pearson χ²(10, N = 292) = 24.64, Lχ²(10, N = 292) = 30.5, p < .01, and between diagnosis and progress toward goals, Pearson χ²(2, N = 390) = 95.296, Lχ²(2, N = 394) = 120.828, p < .001, Cramer’s V = .35. Grounded theory analysis of the interview data revealed a conceptualization of occupational therapy in mental health practice revolving around the intervention process and utilization of assessment and use of theory to guide intervention.

DISCUSSION: The results indicate a significant preference for particular theories by practitioners and an association among theory use, diagnosis, and therapy outcomes. Our results did not find a clear indication in the quantitative data of the type of interventions utilized; however, the qualitative data indicate that interventions were grounded in theoretical conceptual practice models.

IMPACT STATEMENT: This research provides evidence of use of theoretical application to occupational therapy in mental health. As the profession moves back toward its roots in mental health, it is imperative to outline a distinct value of occupational therapy services.